The solutions of the prior art envisage the use of motor means which determine the movement of the doors and also of the blocking/releasing means of the chutes, generally speaking by means of the same transmission belt. In practice, after drawing the doors together to close them the motor means activate the relative blocking/releasing means.
In such a configuration, problems arise in regulating the cage doors: in fact even a slight misalignment of the right side and left side of a door or between the cage door and the corresponding landing door, is sufficient to cause uncomfortable vibrations and movements for the user during the opening and closing movement in proximity of the releasing/blocking area.
Such vibrations, while not constituting a real danger in terms of reliability of the cage, are perceived by users as symptomatic of poor resistance, efficiency and generally poor quality of the cage.